In considering the identity of Paul’s opponents in Galatia, an important datum is that it appears that Paul does not know these people directly by name yet he has enough information about them to describe their activity among the Galatians and make assessments about the truth of what they are teaching. Paul never mentions any opponents by name in Galatians, which is interesting given his penchant for mentioning particular people who opposed him in some fashion: 1 Tim 1:20, Hymenaeus and Alexander; 2 Tim 1:15, Phygelus and Hermogenes; 2 Tim 2:17, Hymenaeus and Philetus; 2 Tim 4:10, Demas (Crescens and Titus are also mentioned here but without negative comment); 2 Tim 4:14, Alexander the coppersmith. A reasonable assumption based on this date is that if he did know the names of these individuals, he would have mentioned them at some point in the letter. Add to this the fact that he sometimes refers to them with either a relative pronoun or an interrogative pronoun (see Gal 3:1; 5:7, 10; 6:12), a reasonable conclusion is that he didn’t know exactly who these people were. It could be that this vague presentation of the opponents is a rhetorical move to minimize their standing in the eyes of the Galatians, similar to how he referred to the Jerusalem apostles not by name in some very particular instances (see Gal 2:2, 6), but this is not the most natural reading of those texts. Even though he mentions no names, however, when Paul does refer to these individuals, he does so with enough specificity that the Galatians certainly knew whom he had in mind. He uses a present participle to designate them in Gal 1:7; 5:10, 12. 6:13. He designates them by action in Gal 4:17; 6:13. He had heard about their effect upon the Galatians and spoke of them in specific enough terms that the Galatians would know exactly whom he had in mind. The short of it is that Paul did not directly know those who were troubling the Galatians, but he knew their activity well enough that he could argue against specific teachings and actions. He had come across these kinds of people before in Jerusalem (see Gal 2:4–5) and in Antioch (see Gal 2:12). The trouble makers in Galatians were cut from the same mold and deserved the same response.
Similarly, Paul readily mentions those who he commends in some fashion. Note for example the long list of specific individuals whom Paul greets or commends in Rom 16. ↩